The aim of this study was to evaluate the clinical significance of 24 hour pH monitoring in the pediatric patients with recurrent vomiting or regurgitation.

We performed 24 hour pH monitoring on 87 pediatric patients with recurrent vomiting or regurgitation using GastrograpH with glass electrode. The pathologic GER was determined by the reflux index (RI). RIs>10% were considered positive in patients <1 year of age, whereas RIs of <5% were positive in other age groups. We evaluated the mean and standard deviation of the reflux parameters between physiologic and pathologic GER groups, and also compared the reflux indices of each group with respect to time zones of the day.

Pathologic GER was found in 32 of 87 patients (36.8%), and the age incidence included 32.5% in infants <6 months old, 13.3% in infants aged 6 months-1 year old, 61.5% in children aged 1~2 years old, 14.3% in children aged 2~3 years old and 66.7% in children >3 years old. In physiologic GER patients, the RI was 3.7±2.9% for the patients <1 year old (group A), and 1.8±1.5% for those > or =1 year old (group B) which was statistically significant between the 2 age groups (p=0.02). The number of long refluxes more than 5 minutes was significantly increased (p=0.03) in group A (1.7±1.9) than in group B (0.8±1.0). The duration of the longest reflux was significantly longer (p=0.007) in group A (604±551 sec) than in group B (275±296 sec). In pathologic GER patients, the RI was 17.7±11.6% for the patients <1 year old and 7.8±2.9 for those > or =1 year old. The number of long refluxes of more than 5 minutes were 8.9±4.6 and 3.2±1.8, and the duration of the longest reflux were 1955±2190 sec and 1093±706 sec for each age group. In both physiologic and pathologic GER patients, there was no significant difference of RI among the time zones of the day.

Pathologic GER was found in 36.8% of patients. There was significant difference of RI between those <1 year old and those > or =1 year old in physiologic GER patients. There was no significant difference of RI among the time zones of the day in both pathologic and physiologic groups. In our study, the frequency of pathplogic GER was too much higher in age group of 1~2 years old (61.5%) than in group of 6 months-1 year old (13.3%), which means that further study is needed to determine the pathologic criteria of RI (Vandenplas criteria is >5%) in the age group of 1~2 years old.